The present invention relates to a rotatable seat, especially to a rotatable seat for preventing falling backwards, which is placed on a seat of a chair or on a flat surface for users to shake their backsides and work out while sitting thereon without falling backwards.
Refer to U.S. Pat. No. 9,788,659 B1, DE 20 2016 101 986, etc., these are prior arts in the field related to rotatable seats/chairs. However the rotatable seat available now is not provided with any safety member for preventing users from falling backwards. When users intend to sit/ride on a seat member of a conventional rotatable seat, the users' legs are wide apart and standing on the ground to keep balance (as the posture shown in FIG. 17). Then the user's center of gravity naturally starts to move backwards until the user's buttocks are mounted in the seat member completely (as the posture shown in FIG. 18) when the user's buttocks are in contact with the seat member. The seat member of the conventional rotatable seat is unbalanced so that it is rotated freely until a stop is reached (as the seat member 10 represented by the dashed line in FIG. 17). Thus the user is easy to rotate along with the seat member and fall backwards during the sitting (as the arrow D and the arrow E in FIG. 18 indicate). There is a risk of injury to the users. Thus there is room for improvement and there is a need to provide a novel rotatable seat.